Chemistry, Matter, and Life (See Word Anatomy at the End of the © Jones & Bartlett Learning,Chapter)

2 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Learning Objectives © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE ORAfter DISTRIBUTION careful study of this chapter, you should NOTbe able FOR to: SALE OR DISTRIBUTION 1 Define a chemical element. p. 22 2 Describe the structure of an atom. p. 22 © Jones & Bartlett Learning, LLC3 Differentiate between ionic© Jones and covalent & Bartlett bonds. p. 24 Learning, LLC NOT FOR SALE OR DISTRIBUTION4 Define an electrolyte. p. NOT24 FOR SALE OR DISTRIBUTION 5 Differentiate between molecules and compounds. p. 25 6 Use chemical equations to illustrate different types of chemical reactions. p. 26 © Jones7 &Define Bartlett mixture; Learning, list the three LLC types of mixtures, and give two ©examples Jones of &each. Bartlett p. 27 Learning, LLC NOT FOR8 Describe SALE roles OR of DISTRIBUTION water in the body. p. 27 NOT FOR SALE OR DISTRIBUTION 9 Compare acids, bases, and salts. p. 28 10 Explain how the numbers on the pH scale relate to acidity and alkalinity. p. 28 © Jones & Bartlett 11Learning, Explain why LLC buffers are important in the body.© Jones p. 29 & Bartlett Learning, LLC NOT FOR SALE OR12 DISTRIBUTION Define radioactivity, and cite several examplesNOT of FORhow radioactive SALE ORsubstances DISTRIBUTION are used in medicine. p. 29 13 Name the three main types of organic compounds and the building blocks of each. p. 30 14 Define enzyme; describe how enzymes work. p. 32 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION15 List the components of NOTnucleotides, FOR and SALE give some OR examples DISTRIBUTION of nucleotides. p. 32 16 Define metabolism, and name the two types of metabolic reactions. p. 34 17 Distinguish between kinetic and potential energy, and give examples of each. p. 34 18 Use the case study to discuss the importance © Jones &of Bartlettregulating bodyLearning, fluid quantity LLC and © Jones & Bartlett Learning, LLC NOT FORcomposition. SALE OR pp. DISTRIBUTION 21, 35 NOT FOR SALE OR DISTRIBUTION 19 Show how word parts are used to build words related to chemistry, matter, and life (see Word Anatomy at the end of the © Jones & Bartlett Learning,chapter). p.LLC 37 © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

© Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION A & P in Action Margaret’s Case: Chemistry’s Role ©in Jones Health & Bartlett Science Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

“Ugh,” sighed Angela as she confirmed the initial diagnosis. Margaret’s electrolyte pulled into her hospital parking levels were out of balance; specifically, she had a high spot. The heat wave was into its blood sodium ion concentration, a condition called © Jones & Bartlettsecond Learning, week, and sheLLC was get- hypernatremia.© Jones Her hematocrit & Bartlett was also Learning, high, indicating LLC NOT FOR SALEting OR tired DISTRIBUTION of it. It was beginning low blood volume.NOT FOR This decrease SALE was OR seriously DISTRIBUTION affecting to take its toll on the city too, especially on its infants and her cardiovascular system. Margaret’s blood pressure had older residents. As Angela walked toward the hospital, she dropped, which forced her heart to beat faster to ensure thought back to yesterday’s ICU shift. One elderly patient proper delivery of blood to her tissues. © Jones &stood Bartlett out in her Learning, mind, probably LLC because she reminded © JonesBecause & Bartlett Margaret Learning, was still conscious LLC and cooperative, Angela of her own grandmother. the emergency team started her on oral rehydration ther- NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION The patient, Margaret Ringland, a 78-year-old widow, apy with an aqueous solution containing small amounts lived alone in her apartment on New York’s Upper East of glucose and salts. Once stabilized, Margaret was moved Side. Yesterday, Margaret’s niece found her collapsed to a hospital bed for observation and recovery. Her level of on the floor, weak and confused. She called 911, and consciousness was monitored, and the staff watched for Margaret was rushed to© the Jones emergency & Bartlett room. According Learning, LLCany signs of cerebral changes© due Jones to the dehydration.& Bartlett Learning, LLC to her medical chart, MargaretNOT FOR presented SALE with OR flushed DISTRIBUTION dry Angela depends on her knowledgeNOT FOR of chemistrySALE OR to DISTRIBUTION skin, a sticky oral cavity, and a furrowed tongue. She was make sense of the signs and symptoms she observes in confused and disoriented. She also had hypotension (low her patients. As you read this chapter, keep in mind that blood pressure) and tachycardia (an elevated heart rate). a firm understanding of the chemistry presented in this All were classic signs of dehydration, a severe deficiency chapter will help you understand the anatomy and physi- of water.© Jones Without & adequate Bartlett water, Learning, Margaret’s LLC body was ology of the© cells, Jones tissues, & andBartlett organ systemsLearning, discussed LLC in unableNOT to perform FOR SALEessential OR metabolic DISTRIBUTION processes, and her subsequentNOT chapters. FOR SALE OR DISTRIBUTION tissues and organs were not in homeostatic balance. Her neurologic symptoms were caused by changes As you study this chapter, CasePoints will give in water volume. Although it was difficult to get a blood you opportunities to apply your learning to this case. sample from Margaret’s flattened veins, her blood work © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Ancillaries At-A-Glance

Visit the web resource to© access Jones the following& Bartlett resources: Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION ● eBook ● A&P Module with Heart & Lung Sounds ● Image Bank ● TestPrep ● Audio© Jones Glossary & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ● WorksheetsNOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION ● Study Aids

Chapter 1 introduced the key idea of levels of organization . In this chapter, we explore the most fundamental level—chemi- Oxygen 65% cals. Future chapters will build on a solid understanding of how chemicals interact in dynamic© Jones ways to& produceBartlett structures Learning, and LLC © Jones & Bartlett Learning, LLC enable body functions. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Introduction Carbon 18.5% Greater understanding of living organisms has come to us through© Joneschemistry &, the Bartlett science thatLearning, deals with LLC the composi- © Jones & Bartlett Learning, LLC tion andNOT properties FOR SALEof matter. OR Knowledge DISTRIBUTION of chemistry and NOT FOR SALE ORHydrogen DISTRIBUTION 9.5% chemical changes helps us understand the body’s normal Nitrogen 3% and abnormal functioning. Food digestion in the intesti- Other 4% nal tract, urine production by the kidneys, the regulation of breathing, and all other body activities involve the prin- FIGURE 2-1 The body’s chemical composition by weight. © Jones &ciples Bartlett of chemistry. Learning, The many LLC drugs used to treat diseases© JonesKEY & POINT Bartlett Oxygen, Learning, carbon, hydrogen, LLC and nitrogen make up NOT FORare SALE also chemicals. OR DISTRIBUTION Chemistry is used for their developmentNOT about FOR 96% SALE of body ORweight. DISTRIBUTION and for understanding their actions in the body. To provide some insights into the importance of chemistry in the life sciences, this chapter briefly describes ele- ATOMIC STRUCTURE ments, atoms, molecules, compounds, and mixtures, which The smallest units of elements are atoms. As such, atoms are fundamental forms of matter. We also describe the © Jones & Bartlett Learning, LLCare the smallest complete units© Jones of matter. & Bartlett They cannot Learning, LLC chemicals that characterize organisms—organic chemicals. NOT FOR SALE OR DISTRIBUTIONbe broken down or changedNOT into anotherFOR SALE form by OR ordi DISTRIBUTION- nary chemical and physical means. Atoms are so small that millions of them could fit on the sharpened end of Elements a pencil. Matter is anything that takes up space, that is, the materi- Despite the fact that the atom is so tiny, chemists have als from© Jones which the & entire Bartlett universe Learning, is made. Elements LLC are the studied it extensively© Jones and & haveBartlett found Learning, that it has a LLCdefinite uniqueNOT substances FOR thatSALE make OR up allDISTRIBUTION matter. The food we eat, structure composedNOT FOR of even SALE smaller, OR or subatomic,DISTRIBUTION particles. the atmosphere, and water—everything around us and every- These particles differ as to their electric charge. Two types thing we can see and touch—are made from just 92 naturally of electric charges exist in nature: positive (+) and nega- occurring elements. (Twenty additional elements have been tive (−). Particles with the same type of charge repel each created in the laboratory.) Examples of elements include vari- other, but particles with different charges attract each other. © Jones &ous Bartlett gases, such Learning, as hydrogen, LLC oxygen, and nitrogen; liquids,© JonesTherefore, & Bartlett a negatively Learning, charged particle LLC would be repelled such as mercury used in barometers and other scientific instru- by another negatively charged particle but attracted by a NOT FORments; SALE and OR many DISTRIBUTION solids, such as iron, aluminum, gold, silver,NOT positively FOR SALE charged OR particle. DISTRIBUTION At the center of each atom is a and zinc. Graphite (the so-called “lead” in a pencil), coal, char- nucleus composed of positively charged particles called pro coal, and diamonds are different forms of the element carbon. tons (PRO-tonz) and noncharged particles called neutrons Elements can be identified by their names or their chem- (NU-tronz) (FIG. 2-2). Together, the protons and neutrons ical symbols, which are abbreviations of their modern or contribute nearly all of the atom’s weight. Latin names. Each element© Jones is also identified & Bartlett by its Learning,own num- LLCIn orbit around the nucleus© areJones electrons & Bartlett(e-LEK-tronz). Learning, LLC ber, which is based on itsNOT atomic FOR structure, SALE discussed OR DISTRIBUTION shortly. These nearly weightless particlesNOT are FOR negatively SALE charged. OR DISTRIBUTION The periodic table is a chart used by chemists to organize The protons and electrons of an atom are equal in num- and describe the elements. Appendix 1 shows the periodic ber so that the atom as a whole is electrically neutral (see table and gives some information about how it is used. FIG. 2-2). As discussed later, it is the electrons that determine Of the 92 elements that exist in nature, only 26 have how (or if) the atom will participate in chemical reactions. been ©found Jones in living & Bartlettorganisms. Learning, Hydrogen, oxygen, LLC carbon, Atoms may© gain Jones or lose &electrons Bartlett in these Learning, reactions andLLC thus and nitrogenNOT FOR make SALEup about OR 96% DISTRIBUTION of body weight (FIG. 2-1). become electricallyNOT FOR charged. SALE OR DISTRIBUTION Nine additional elements—calcium, sodium, potassium, The atomic number of an element is equal to the num- phosphorus, sulfur, chlorine, magnesium, iron, and iodine— ber of protons that are present in the nucleus of its atoms. make up most of the remaining 4% of the body’s elements. Because the number of protons is equal to the number of The remaining 13, including zinc, selenium, copper, cobalt, electrons, the atomic number also represents the number of © Jones &chromium, Bartlett and Learning, others, are present LLC in extremely small (trace)© Joneselectrons & Bartlettorbiting the Learning, nucleus. As youLLC can see in FIGURE 2-2, NOT FORamounts SALE totaling OR DISTRIBUTION about 0.1% of body weight. TABLE 2-1 listsNOT oxygen FOR hasSALE an atomic OR DISTRIBUTIONnumber of 8. No two elements share some of these elements along with their functions. the same atomic number. Oxygen is the only element with

Oxygen O Part of water; needed to metabolize nutrients for energy Carbon C © Jones Basis& Bartlett of all organic Learning, compounds; componentLLC of carbon dioxide, the gaseous© Jones byproduct & Bartlettof metabolism Learning, LLC Hydrogen H NOT FORPart SALE of water; OR participates DISTRIBUTION in energy metabolism; determines the acidityNOT of FOR body fluidsSALE OR DISTRIBUTION Nitrogen N Present in all proteins, ATP (the energy-storing compound), and nucleic acids (DNA and RNA) Calcium Ca Builds bones and teeth; needed for muscle contraction, nerve impulse conduction, and blood clotting Phosphorus© Jones &P Bartlett Learning,Active ingredient LLC in ATP; builds bones and teeth;© Jonescomponent & of Bartlett cell membranes Learning, and nucleic LLC acids PotassiumNOT FOR KSALE OR DISTRIBUTIONActive in nerve impulse conduction; muscle contractionNOT FOR SALE OR DISTRIBUTION Sulfur S Part of many proteins Sodium Na Active in water balance, nerve impulse conduction, and muscle contraction Iron Fe Part of hemoglobin, the compound that carries oxygen in red blood cells

the atomic number of 8. As another example, a carbon atom The positively charged protons keep the negatively has six protons in the nucleus and six electrons orbiting the charged electrons in orbit around the nucleus by means of nucleus, so the atomic number© Jones of carbon & Bartlett is 6. In the Learning, Periodic LLCthe opposite charges on the© particles. Jones Positively& Bartlett charged Learning, LLC Table of the Elements (see Appendix 1), the atomic number protons attract negatively charged electrons. is located at the top of theNOT box FOR for each SALE element. OR The DISTRIBUTION atomic NOT FOR SALE OR DISTRIBUTION weight (mass), the sum of the protons and neutrons, is the Energy Levels An atom’s electrons orbit at specific dis- number at the bottom of each box. It takes about 1,850 tances from the nucleus in regions called energy levels (see electrons to equal the weight of a single neutron or proton, FIG. 2-2). The first energy level, the one closest to the nucleus, so electrons are not counted in the determination of atomic can hold only two electrons. The second energy level, the weight.© Jones & Bartlett Learning, LLC next in distance© Jones away from & Bartlett the nucleus, Learning, can hold up LLCto eight NOT FOR SALE OR DISTRIBUTION electrons. FIGURENOT 2-3AFOR shows SALE the ORoxygen DISTRIBUTION atom with only the protons in the nucleus and the electrons in fixed posi- First energy level tions in their energy levels. It has two electrons in its first Electron energy level and six electrons in its second, outermost, level. The carbon atom, with an atomic number of 6, has four © Jones & Bartlett Learning, LLC © Joneselectrons & Bartlettin its outermost Learning, energy levelLLC (see FIG. 2-3B). More NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Second energy Electron Second level energy © Jones & Bartlett Learning, LLC © Jones & Bartlettlevel Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION + + Central nucleus 8p 6p Eight protons (red) Second Eight neutrons (green) energy © Jones & Bartlett Learning, LLClevel © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION OxygenNOT (O) FOR SALE ORCarbon DISTRIBUTION (C) FIGURE 2-2 Representation of the oxygen atom. KEY A B POINT Eight protons and eight neutrons are tightly bound in the central nucleus. The eight electrons are in orbit around the nucleus, FIGURE 2-3 Examples of atoms. KEY POINT The first energy two in the first energy level, and six in the second. ZOOMING IN level can hold two electrons, and the second and third can hold © Jones &How Bartlett does the number Learning, of protons LLC in this atom compare with the © Joneseight. The & outermostBartlett energy Learning, level determines LLC chemical reactivity. NOT FORnumber SALE of electrons?OR DISTRIBUTION See Appendix 2 for answers to the Zooming In NOT FORZOOMING SALE IN How OR many DISTRIBUTION electrons does oxygen need to questions complete its outermost energy level?

© Jones distant& Bartlett energy Learning,levels can hold LLC more than eight electrons, but© Jones & Bartlett Learning,Electron LLC NOT FORthey SALE are stable OR (nonreactive)DISTRIBUTION when they have eight. NOT FOR SALE OR DISTRIBUTION The electrons in the energy level farthest away from the nucleus determine how the atom will react chemically. Atoms can donate, accept, or share electrons with other 11p 17p atoms to make the outermost level complete. In so doing, they form chemical bonds,© Jones as described & Bartlett shortly. Atoms Learning, with LLC © Jones & Bartlett Learning, LLC a stable number of electronsNOT FORin the outermostSALE OR energy DISTRIBUTION level NOT FOR SALE OR DISTRIBUTION do not participate in chemical reactions. Examples are the inert or “noble” gases, including helium, neon, and argon. Sodium atom Chlorine atom A CHECKPOINTS Elec © Jones & Bartlett Learning, LLC © Jones & Bartletttro Learning, LLC 2-1 What are atoms? n 2-2NOT What FOR are three SALE types ofOR particles DISTRIBUTION found in atoms? NOT FOR SALE OR DISTRIBUTION 2-3 Which of these atoms would be more likely to participate in a chemical reaction—an atom with eight electrons in 11p 17p its outermost energy level or an atom with six electrons in its outermost energy level? © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC See Appendix 2 for answers to the Checkpoint questions. NOT FOR SALE OR DISTRIBUTION NOT FORSodium SALE ion OR (Na+ DISTRIBUTION) Chloride ion (Cl–) Chemical Bonds B When an atom interacts with other atoms to stabilize its outermost energy level, a bond is formed between the atoms. In these chemical reactions,© electronsJones may& Bartlett be transferred Learning, from LLC © Jones & Bartlett Learning, LLC + – one atom to another orNOT may be FOR shared SALE between OR atoms. DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 11p 17p IONIC BONDS When electrons are transferred from one atom to another, the type© Jones of bond &formed Bartlett is called Learning, an ionic (i-ON-ik) LLC bond. © Jones & Bartlett Learning, LLC The sodiumNOT FORatom, forSALE example, OR tends DISTRIBUTION to lose the single elec- NOTNa FOR+ SALE ORCl DISTRIBUTION– tron in its outermost shell leaving the now outermost shell Sodium chloride with a stable number of electrons (eight) (FIG. 2-4). Removal C (table salt) of a single electron from the sodium atom leaves one more proton than electrons, and the sodium then has a single net FIGURE 2-4 Ionic bonding. A. A sodium atom has 11 protons © Jones &positive Bartlett charge. Learning, The sodium LLC in this form is symbolized as© Jonesand 11 electrons.& Bartlett A chlorine Learning, atom has 17 LLC protons and 17 electrons. Na+. Calcium loses two electrons when it participates in NOT FOR SALE OR DISTRIBUTION NOTB. FOR A sodium SALE atom gives OR up DISTRIBUTION one electron to a chlorine atom in ionic bonds, so the calcium ion has two positive charges forming an ionic bond. The sodium atom now has 11 protons and 2+ and is abbreviated Ca . 10 electrons, resulting in a positive charge of one. The chlorine Alternately, atoms can gain electrons so that there are becomes negatively charged by one, with 17 protons and more electrons than protons. Chlorine, which has seven elec- 18 electrons. C. The ionic bond between the sodium ion (Na+) trons in its outermost energy level, tends to gain one elec- − © Jones & Bartlett Learning, LLCand the chloride ion (Cl ) forms the© compound Jones sodium & Bartlett chloride Learning, LLC tron to fill the level to its capacity. The resultant chlorine is (table salt). ZOOMING IN How many electrons are in the −NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION negatively charged (Cl ) (see FIG. 2-4). (Chemists refer to this outermost energy level of a sodium atom? Of a sodium ion? charged form of chlorine as chloride.) An atom or group of atoms that has acquired a positive or negative charge is called an ion (I-on). Any ion that is positively charged is a substances tend to form crystals when solid and to dissolve cation (CAT-i-on). Any negatively charged ion is an anion easily in water. (AN-i-on).© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ImagineNOT FOR a sodium SALE atom OR coming DISTRIBUTION in contact with a ElectrolytesNOT When FOR ionically SALE bonded OR DISTRIBUTIONsubstances dissolve chlorine atom. The sodium atom gives up its outermost in water, the atoms separate as ions. Compounds that electron to the chlorine and becomes positively charged; release ions when they dissolve in water are called electro the chlorine atom gains the electron and becomes nega- lytes (e-LEK-tro-lites). Note that in practice, the term elec- tively charged. The two newly formed ions (Na+ and Cl−), trolytes is also used to refer to the ions themselves in body © Jones &because Bartlett of their Learning, opposite charges, LLC attract each other to pro©- Jonesfluids. & Electrolytes Bartlett include Learning, a variety LLC of salts, such as sodium NOT FORduce SALE sodium OR chloride, DISTRIBUTION ordinary table salt (see FIG. 2-4). TheNOT chloride FOR SALE and potassium OR DISTRIBUTION chloride. They also include acids attraction between the oppositely charged ions forms an and bases, which are responsible for the acidity or alkalinity ionic bond. Sodium chloride and other ionically bonded of body fluids, as described shortly.

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE ConORc eptDISTRIBUTION Mastery Alert NOT FOR SALE OR DISTRIBUTION In all cases, a salt consists of a positively charged cation + + 2 and a negatively charged anion joined by an ionic bond.

Hydrogen molecule (H ) Electrolytes must ©be Jonespresent in& theBartlett proper concentraLearning,- LLC © Jones2 & Bartlett Learning, LLC tions in the intracellular and extracellular fluids, or dam- FIGURE 2-5 A nonpolar covalent bond. KEY POINT aging effects will result,NOT as seen FOR in Margaret’sSALE OR case DISTRIBUTION study, NOT FOR SALE OR DISTRIBUTION The electrons involved in the bonding of two hydrogen atoms which opens this chapter. are equally shared between the two atoms. The electrons orbit evenly around the two. ZOOMING IN How many electrons are Ions in the Body Body fluids contain many different ions. needed to complete the energy level of each hydrogen atom in the Indeed, many of the elements listed in TABLE 2-1 are only active© in Jones their ionic & Bartlett forms. Sodium Learning, (Na+) and LLC potassium hydrogen molecule?© Jones & Bartlett Learning, LLC (K+) ions,NOT for FOR instance, SALE play OR critical DISTRIBUTION roles in the transmis- NOT FOR SALE OR DISTRIBUTION sion of electric signals by virtue of their positive charges. hydrogen, oxygen, or nitrogen (FIG. 2-5). Electrons may also The concentration of many different ions in body fluids be shared equally in some bonds involving different atoms— must be kept within narrow limits in order to maintain methane (CH4), for example. If electrons are equally shared homeostasis. in forming a bond, the electric charges are evenly distributed © Jones & BartlettBecause ions Learning, are charged LLC particles, electrolytic solutions© Jonesaround & the Bartlett atoms and Learning, the bond is LLC described as a nonpolar NOT FORcan SALE conduct OR an DISTRIBUTIONelectric current. Records of electric currentsNOT covalent FOR SALE bond. That OR is, DISTRIBUTION no part of the combined particle is in tissues are valuable indications of the functioning or mal- more negative or positive than any other part. More com- functioning of tissues and organs. The electroencephalogram monly, the electrons are held closer to one atom than the (e-lek-tro-en-SEF-ah-lo-gram) and the electrocardiogram other, as in the case of water (H2O), shown in FIGURE 2-6. In (e-lek-tro-KAR-de-o-gram) are graphic tracings of the elec- water, the shared electrons are actually closer to the oxygen tric currents generated© by Jones the brain & andBartlett the heart Learning, muscle, LLCatom than the hydrogen atoms© atJones any one & time, Bartlett making Learning, the LLC respectively (see Chapters 9 and 13). oxygen region more negative. Such bonds are called polar NOT FOR SALE OR DISTRIBUTIONcovalent bonds, because one NOTregion FOR of the SALE combination OR DISTRIBUTIONis more negative and one part is more positive at any one time. COVALENT BONDS

Although ionic bonds form some chemicals, many more are Concept Mastery Alert formed© byJones another & type Bartlett of chemical Learning, bond. This LLCbond involves © Jones & Bartlett Learning, LLC not the exchange of electrons but a sharing of electrons Remember that electrons are transferred in ionic bonds but betweenNOT the FORatoms SALEand is called OR aDISTRIBUTION covalent bond. This name shared (equallyNOT or FORunequally) SALE in covalent OR DISTRIBUTION bonds. comes from the prefixco -, meaning “together,” and valence, referring to the electrons involved in chemical reactions between atoms. In a covalently bonded substance, the shared MOLECULES AND COMPOUNDS electrons orbit around both of the atoms, making both of When two or more atoms unite covalently, they form a © Jones &them Bartlett stable. Covalent Learning, bonds LLCmay involve the sharing of one,© Jonesmolecule & Bartlett(MOL-eh-kule). Learning, A molecule LLC is thus the smallest NOT FORtwo, SALE or three OR pairs DISTRIBUTION of electrons between atoms. NOTunit FOR of aSALE covalently OR bondedDISTRIBUTION substance that retains all the In some covalent bonds, the electrons are equally properties of that substance. A molecule can be made of shared, as in the combination of two identical atoms of like atoms—the oxygen molecule is made of two identical

OO+ – © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION H NOT FOR SALE OR DISTRIBUTION H +

FIGURE 2-6 Formation of water. KEY POINT Polar covalent bonds form © Jones & Bartlett Learning,water. LLC The unequal sharing of electrons© makesJones the region& Bartlett near the oxygenLearning, LLC NOT FOR SALE OR DISTRIBUTIONnucleus more negative and the regionNOT near the FOR hydrogen SALE nucleus OR more DISTRIBUTION positive. ZOOMING IN How many hydrogen atoms bond with an oxygen atom to form water?

© Jones atoms,& Bartlett for example—but Learning, more LLC often a molecule is made© Jonesone atom & Bartlett of oxygen Learning,(O). Other compounds LLC have very large NOT FORof SALE atoms ofOR two DISTRIBUTION or more different elements. For example,NOT and FOR complex SALE molecules. OR DISTRIBUTION Such complexity characterizes

a water molecule (H2O) contains one atom of oxygen (O) many of the compounds found in living organisms. Some and two atoms of hydrogen (H) (see FIG. 2-6). Any particle protein molecules, for example, have thousands of atoms. resulting from a polar covalent bond is known as a polar It is interesting to observe how different a compound molecule. Some polar molecules can gain or lose electrons is from any of its constituents. For example, a molecule of − and thus become ions.© JonesBicarbonate & Bartlett ions (HCO Learning,3 ), for LLCliquid water is formed from© oxygen Jones and & hydrogen,Bartlett bothLearning, LLC instance, participate inNOT the regulation FOR SALE of body OR fluid DISTRIBUTION acidity. of which are gases. Another NOTexample FOR is the SALE sugar ORglucose DISTRIBUTION Polar molecules, whether they are charged or uncharged, (C6H12O6). Its constituents include 12 atoms of the gas can interact using weak bonds called hydrogen bonds, as hydrogen, six atoms of the gas oxygen, and six atoms of the discussed in BOX 2-1. solid element carbon. The component gases and the solid Note that chemists do not consider ionically bonded carbon do not in any way resemble the glucose. substances© Jones to be composed& Bartlett of molecules, Learning, as their LLC atoms are © Jones & Bartlett Learning, LLC held togetherNOT FOR by electrical SALE attractionOR DISTRIBUTION only. The bonds that NOT FOR SALE OR DISTRIBUTION hold these atoms together are weak, and the components CHEMICAL EQUATIONS separate easily in solution into ions, as already described. In the everyday chemical reactions of life, atoms are not cre- Thus, unlike ionic bonds and hydrogen bonds, only cova- ated or destroyed; they are only rearranged by the forma- lent bonds form molecules. tion and destruction of chemical bonds. A chemical equation © Jones & Bartlett Learning, LLC © Jonesis a shorthand & Bartlett way Learning,to represent aLLC chemical reaction. Like Concept Mastery Alert NOT FOR SALE OR DISTRIBUTION NOTEnglish FOR SALEsentences, OR chemical DISTRIBUTION equations are usually read left Remember that, ionic bonds, but not covalent bonds, form to right. The molecules to the left of the sideways arrow salts. react together to form the products to the right of the arrow. For instance, in the equation below, A and B react together Any substance composed of two or more different ele- to form C. The single arrow indicates the reaction is not ments is called a compound© Jones. This &definition Bartlett includes Learning, both LLCreversible. That is, C does not© break Jones down & into Bartlett A and B. Learning, LLC ionically and covalently bonded substances. The formula AB+→C for a compound showsNOT all the FOR elements SALE that ORmake DISTRIBUTION up that NOT FOR SALE OR DISTRIBUTION

compound in their proper ratio, such as NaCl, H2O, and However, many chemical reactions are reversible. In

CO2. Some compounds are made of a few elements in a that case, the chemical equation includes arrows in both simple combination. For example, molecules of the gas car- directions. The following chemical equation illustrates that D and E combine to form F, but F can also be broken down bon monoxide© Jones (CO) & Bartlett contain one Learning, atom of carbon LLC (C) and © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION A CLOSER LOOK BOX 2-1 Hydrogen Bonds: Strength in Numbers

© Jones & BartlettIn contrast Learning,to ionic and covalent LLC bonds, which hold atoms© Jonesdimensional & Bartlett structure Learning,of proteins. Because LLC a protein’s struc- NOT FOR SALEtogether, OR hydrogen DISTRIBUTION bonds hold molecules together. HydrogenNOT ture FOR determines SALE its OR function DISTRIBUTION in the body, hydrogen bonds are bonds are much weaker than ionic or covalent bonds—in fact, essential to protein activity. they are more like “attractions” between molecules. While ionic and covalent bonds rely on electron transfer or sharing, hydrogen bonds form bridges between two molecules. A hydrogen bond forms when a slightly© Jones positive & hydrogenBartlett atom Learning, in one LLC © Jones & Bartlett Learning, LLC molecule is attracted NOTto a slightly FOR negative SALE atom OR in DISTRIBUTION another NOT FOR SALE OR DISTRIBUTION molecule. Even though a single hydrogen bond is weak, many hydrogen bonds between two molecules can be strong. Water Hydrogen bonds hold water molecules together, with the Hydrogen slightly positive hydrogen atom in one molecule attracted to molecules bonds + a slightly negative oxygen atom in another. Many of water’s – unique© Jones properties & Bartlettcome from Learning, its ability to formLLC hydrogen © Jones & Bartlett Learning, LLC bonds.NOT For FOR example, SALE hydrogen OR bonds DISTRIBUTION keep water liquid over a NOT FOR SALE ORO DISTRIBUTIONH wide range of temperatures, which provides a constant environment for body cells. Hydrogen bonds form not only between molecules H but also within large molecules. Hydrogen bonds between © Jones & Bartlettregions of the Learning, same molecule LLC cause it to fold and coil into ©a JonesHydrogen & Bartlett bonds. The Learning, bonds shown hereLLC are holding water NOT FOR SALEspecific OR shape, DISTRIBUTION as in the process that creates the precise three-NOT moleculesFOR SALE together. OR DISTRIBUTION

© Jones into& Bartlett D and E. IfLearning, both reactions LLC occur at the same frequency,© Jones & Bartlett Learning, LLC NOT FORthe SALE chemical OR reaction DISTRIBUTION is at equilibrium. For instance, in thisNOT FORTable SALE 2-2 ORMixtures DISTRIBUTION chemical reaction at equilibrium, the rate of F formation is 2 equal to the rate of F breakdown. The concentration of each Type Definition Example substance will remain constant. Solution Homogeneous mixture Table salt (NaCl) ©DE Jones+ F & Bartlett Learning, LLC formed when one© Jones dissolved& Bartlett in Learning, LLC substance (solute) water; table sugar In chemical reactionsNOT that FOR are not SALE at equilibrium, OR DISTRIBUTION one dissolves in anotherNOT FOR(sucrose) SALE dissolved OR DISTRIBUTION reaction occurs more frequently than the other. For instance, (solvent) in water if the rate of F formation exceeds the rate of F breakdown, Suspension Heterogeneous mixture Red blood cells the concentrations of D and E will decrease and the concen- in which one substance in blood plasma; tration of F will increase. is dispersed in another milk of magnesia These© Jones simple &illustrations Bartlett do Learning, not cover all LLC the variables © Jonesbut will settle & Bartlett out unless Learning, LLC that mayNOT affect FOR chemical SALE reactions OR DISTRIBUTION but provide a basis for NOTconstantly FOR mixedSALE OR DISTRIBUTION interpreting chemical equations. More examples will appear Colloid Heterogeneous mixture Blood plasma; later in the text as we explore various physiologic processes. in which the suspended cytosol particles remain evenly distributed based on the CHECKPOINTS small size and opposing © Jones & Bartlett2-4 Which Learning,type of chemical LLC bond is formed by an exchange© Jones & Bartlettcharges Learning, of the particles LLC NOT FOR SALEof ORelectrons? DISTRIBUTION Which type is formed by a sharing ofNOT FOR SALE OR DISTRIBUTION electrons? 2-5 What happens when an electrolyte goes into solution? the material in which they are dispersed, and they settle out 2-6 What are molecules, and what are compounds? because they are large and heavy. Examples of suspensions are milk of magnesia, finger paints, and in the body, red 2-7 Write a chemical equation to show that substance X reacts © Jones & Bartlett Learning, LLCblood cells suspended in blood© plasma. Jones & Bartlett Learning, LLC with substance Y to form Z and that the reaction is reversible. NOT FOR SALE OR DISTRIBUTIONOne other type of mixtureNOT is important FOR SALE in body OR func DISTRIBUTION- tion. Some organic compounds form colloids, in which the molecules do not dissolve yet remain evenly distributed in Mixtures the suspending material. The particles have electric charges Not all elements or compounds react chemically when that repel each other, and the molecules are small enough to brought© Jonestogether. &The Bartlett air we breathe Learning, every day LLC is a combi- stay in suspension.© Jones The &fluid Bartlett that fills Learning, the cells (cytosol) LLC is a nationNOT of gases, FOR largely SALE nitrogen, OR DISTRIBUTIONoxygen, and carbon diox- colloid, as isNOT blood FOR plasma. SALE OR DISTRIBUTION ide, along with smaller percentages of other substances. The Many mixtures are complex, with properties of solu- constituents in the air maintain their identity, although the tions, suspensions, and colloids. For instance, blood plasma proportions of each may vary. Blood plasma—the fluid por- has dissolved compounds, making it a solution. The red blood tion of blood—is also a combination in which the various cells and other formed elements give blood the property of a © Jones &components Bartlett maintain Learning, their identity. LLC The many valuable com©- Jonessuspension. & Bartlett The proteins Learning, in the plasma LLC give it the property of pounds in the plasma remain separate entities with their own a colloid. Chocolate milk also has all three properties. NOT FORproperties. SALE OR Such DISTRIBUTION combinations are called mixtures—blendsNOT FOR SALE OR DISTRIBUTION of two or more substances (TABLE 2-2). CASEPOINTS 2-1 What type of solution did the emergency team adminis- SOLUTIONS AND SUSPENSIONS ter orally to Margaret in the opening case study? 2-2 Name the solvent in this solution. A mixture formed when© one Jones substance & dissolvesBartlett in Learning,another is LLC © Jones & Bartlett Learning, LLC called a solution. One exampleNOT FOR is salt water.SALE In aOR solution, DISTRIBUTION the NOT FOR SALE OR DISTRIBUTION component substances cannot be distinguished from each THE IMPORTANCE OF WATER other and remain evenly distributed throughout; that is, the Water is the most abundant compound in the body. No plant mixture is homogeneous (ho-mo-JE-ne-us). The dissolving or animal can live very long without it. Water is of critical substance, which is water in the body, is the solvent. The sub- importance in all physiological processes in body tissues. A stance© dissolved, Jones table& Bartlett salt in the Learning, case of salt water, LLC is the sol deficiency ©of Joneswater, or & dehydration Bartlett (de-hi-DRA-shun),Learning, LLC can ute. AnNOT aqueous FOR (A-kwe-us) SALE OR solution DISTRIBUTION is one in which water be a seriousNOT threat FORto health, SALE as illustrated OR DISTRIBUTION by Margaret’s case is the solvent. Aqueous solutions of glucose, salts, or both of study. Water carries substances to and from the cells and makes these together are used for intravenous fluid treatments. possible the essential processes of absorption, exchange, secre- In some mixtures, the substance distributed in the back- tion, and excretion. What are some of the properties of water ground material is not dissolved and will settle out unless that make it such an ideal medium for living cells? © Jones &the Bartlett mixture is Learning, constantly shaken. LLC This type of nonuniform,© Jones & Bartlett Learning, LLC NOT FORor SALE heterogeneous OR DISTRIBUTION (het-er-o-JE-ne-us), mixture is called NOTa ■ FOR Water SALE can dissolve OR DISTRIBUTION many different substances in large suspension. The particles in a suspension are separate from amounts. For this reason, it is called the universal

© Jones & Bartlettsolvent. Many Learning, of the body’s LLC necessary materials, such© Jonesof hydrogen & Bartlett ions increases, Learning, the concentration LLC of hydroxide NOT FOR SALEas gases OR and DISTRIBUTION nutrients, dissolve in water to be carNOT- ions FOR decreases. SALE Conversely, OR DISTRIBUTION as the concentration of hydrox- ried from place to place. Substances, such as salt, that ide ions increases, the concentration of hydrogen ions mix with or dissolve in water are described as hydro decreases. philic (“water-loving”); substances, such as fats, that Acidity and alkalinity are indicated by pH units, which do not dissolve in water are described as hydrophobic represent the relative concentrations of hydrogen and (“water-fearing”).© Jones & Bartlett Learning, LLChydroxide ions in a solution.© The Jones pH units & Bartlettare listed onLearning, a LLC scale from 0 to 14, with 0 being the most acidic and 14 ■ Water is stable asNOT a liquid FOR at ordinarySALE ORtemperatures. DISTRIBUTION NOT FOR SALE OR DISTRIBUTION It does not freeze until the temperature drops to 0°C being the most basic (FIG. 2-7). A pH of 7.0 is neutral. At (32°F) and does not boil until the temperature reaches pH 7.0, the solution has an equal number of hydrogen and 100°C (212°F). This stability provides a consistent hydroxide ions. Pure water has a pH of 7.0. Solutions that environment for living cells. Water can also be used to measure less than 7.0 are acidic; those that measure above distribute© Jones heat & throughoutBartlett Learning, the body and LLC to cool the 7.0 are alkaline© Jones (basic). & Bartlett Learning, LLC bodyNOT by FOR evaporation SALE of ORsweat DISTRIBUTION from the body surface. BecauseNOT the pH FOR scale SALEis based ORon multiples DISTRIBUTION of 10, each pH unit on the scale represents a 10-fold change in the ■ Water participates in the body’s chemical reactions. It is number of hydrogen and hydroxide ions present. A solu- needed directly in the digestive process and in many of tion registering 5.0 on the scale has 10 times the number of the metabolic reactions that occur in the cells. hydrogen ions as a solution that registers 6.0. The pH 5.0 © Jones & Bartlett Learning, LLC © Jonessolution & alsoBartlett has one-tenth Learning, the number LLC of hydroxide ions as CHECKPOINTS the solution of pH 6.0. A solution registering 9.0 has one- NOT FOR SALE OR DISTRIBUTION NOTtenth FOR the SALE number OR of hydrogen DISTRIBUTION ions and 10 times the number 2-8 What is the difference between solutions and suspensions? of hydroxide ions as one registering 8.0. Thus, the lower the 2-9 What is the most abundant compound in the body? pH reading, the greater is the acidity, and the higher the pH, the greater is the alkalinity. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Acids, Bases, and Salts Increasing acidity NOT FOR SALE OR DISTRIBUTION + – NOT FOR SALE OR DISTRIBUTION An acid (AH-sid) is a chemical substance capable of releas- H > OH pH + ing a hydrogen ion (H ) when dissolved in water. A com- 0 mon example is hydrochloric acid (HCl), the acid found in stomach juices. HCl releases hydrogen ions in solution as ACID 1 follows: Stomach secretions (1.5) © Jones & Bartlett Learning, LLC © Jones &2 BartlettLemon Learning, juice (2.0) LLC NOT FORHC SALELH→+ OR +DISTRIBUTIONCl− NOT FOR SALEColas OR (2.5) DISTRIBUTION (hydrochloric acid) (hydrogen ion) (chloride ion) 3 Apple juice (3.0)

A base is a chemical substance that can accept (react 4 Tomato juice (4.2) with) a hydrogen ion. A base is also called an alkali (AL-kah-li), and bases are described as alkaline. Most bases 5 Coffee (5.0) release a hydroxide ion (OH−) in solution, and the hydrox- © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning,6 LLC NOT FORide SALE ion subsequently OR DISTRIBUTION accepts a hydrogen ion to form water.NOT FOR SALE OR DISTRIBUTIONMilk, saliva (6.5) Sodium hydroxide is an example of a base: Neutral 7 Distilled water (7.0) Human blood (7.4) NaOH→+ Na+ OH− 8 (sodium hydroxide) ( sodium ionh) ( ydroxide ion) Sodium bicarbonate (8.4) OH−++→HHO 9 © Jones &2 Bartlett Learning, LLC © BleachJones (9.5) & Bartlett Learning, LLC A reaction between an acid and a base produces a salt 10 NOT FOR SALE OR DISTRIBUTION NOTMilk FORof magnesia SALE (10.5) OR DISTRIBUTION and also water. In the reaction, the hydrogen of the acid is 11 replaced by the positive ion of the base. A common example Household ammonia (11.5) of a salt is sodium chloride (NaCl), or table salt, produced 12 by the reaction: BASE 13 Lye (13)

© JonesHC &lN +→BartlettaOHN Learning,aClH+ 2O LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR14 SALE OR DISTRIBUTION Increasing basicity (alkalinity) – + THE PH SCALE OH > H The greater the concentration of hydrogen ions in a solu- FIGURE 2-7 The pH scale. Degree of acidity or alkalinity is tion, the greater the acidity of that solution. The greater shown in pH units. This scale also shows the pH of some common © Jones &the Bartlett concentration Learning, of hydroxide LLC ion (OH−), the greater the© Jonessubstances. & Bartlett ZOOMING Learning, IN What happens LLC to the amount of NOT FORalkalinity SALE ORof the DISTRIBUTION solution. The concentrations of H+ andNOT hydroxide FOR SALE ion (OH− )OR present DISTRIBUTION in a solution when the amount of OH− in a solution are inversely related; as the concentration hydrogen ion (H+) increases?

If you’ve ever golfed or skied, you may have experienced Solution this phenomenon—you© Jonesperform &very Bartlett well on the Learning, practice LLCStep 1. Before attempting© to Jonessolve the &problem, Bartlett it can Learning, LLC range or an easy slope,NOT but FORthen you SALE revert OR to bad DISTRIBUTION habits be handy to write out a mnemonic.NOT You FORcan use SALE “H+AL” (hydro OR- DISTRIBUTION when you hit the golf course or a difficult ski run. The same gen ion, acidity, low pH). If you are more of a visual person, thing can happen in an exam, when the stress causes us to you might want to draw a pH line similar to FIGURE 2-7 on revert to our ingrained (dominant) habits. Athletes develop the question or exam sheet, including changes in hydrogen/ rituals to ensure that their practice carries over to competi- hydroxide ion concentrations and pH values. You also need to tive situations. You can do the same to maximize your exam © Jones & Bartlett Learning, LLC remember that© 7Jones is neutral. & Bartlett Learning, LLC performance. Step 2. Find the pH value in the question—in this exam- NOTStudents FOR frequently SALE make OR errors DISTRIBUTION in questions about pH, ple, 7.28. If youNOT drew FOR the number SALE line, OR write DISTRIBUTION this value on the even upper-year and medical students. It may seem logical line. Note that 7.28 is situated in the basic (alkaline) portion of that higher pH equates with more hydrogen ions, but the the line, where hydroxide ions exceed hydrogen ions. opposite is true. To avoid making a mistake on your exam, If you used the mnemonic, your starting point is that this develop a pH question routine. number is higher than 7—it is a high pH. So, based on the mne- © Jones & Bartlett Learning, LLC © Jonesmonic, &high Bartlett pH is basic Learning, (not acidic), and LLC hydroxide (not hydro- NOT FOR SALEQuestion OR DISTRIBUTION NOTgen) FOR ions SALE are the most OR abundant. DISTRIBUTION The case study focuses on Margaret, an elderly lady with Step 3. Answer parts A and B. Based on the work in step severe dehydration. Margaret’s blood pH upon admission 2, her blood is alkaline and contains more hydroxide ions than was 7.28. hydrogen ions. Step 4. Part C tells us that her blood pH is lower than the a. Are solutions with this pH considered to be basic (alkaline) normal range. Go back to the mnemonic—low pH is associ- or acidic? © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ated with acidity and hydrogen ions. So her blood contains b. Does her blood contain more hydrogen ions or more NOT FOR SALE OR DISTRIBUTIONmore hydrogen ions than normal.NOT FOR SALE OR DISTRIBUTION hydroxide (OH−) ions? c. The normal pH range for blood is 7.35 to 7.45. Does Whatever approach you take, use the same approach in prac- her blood contain more or fewer hydrogen ions than tice problems and exams. Taking the time for your “pre-ques- normal? tion ritual” will increase your accuracy and help prevent errors. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Blood and other body fluids are close to neutral but in hydrogen ion concentration and thus maintains a rela- are slightly on the alkaline side, with a pH range of 7.35 to tively constant pH. Buffers are important in maintaining 7.45. Urine averages pH 6.0 but may range from 4.6 to 8.0 stability in the pH of body fluids. More information about depending on body conditions and diet. FIGURE 2-7 shows body fluids, pH, and buffers can be found in Chapter 19. the pH of some other common substances. © Jones & BartlettBecause body Learning, fluids are LLC on the alkaline side of neutral,© JonesCHECKPOINTS & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION the body may be in a relatively acidic state even if the pH 2-10 What number is neutral on the pH scale? What kind of does not drop below 7.0. For example, if a patient’s pH compound measures lower than this number? Higher? falls below 7.35 but is still greater than 7.0, the patient 2-11 What is a buffer? is described as being in an acidic state known as acidosis. Thus, within this narrow range, physiologic acidity differs from acidity as defined© by Jones the pH scale.& Bartlett Learning, LLC © Jones & Bartlett Learning, LLC An increase in pHNOT to readings FOR SALE greater ORthan DISTRIBUTION 7.45 is Isotopes and RadioactivityNOT FOR SALE OR DISTRIBUTION termed alkalosis. Any shifts in pH to readings above or Elements may exist in several forms, each of which is called below the normal range can be dangerous, even fatal. See an isotope (I-so-tope). These forms are alike in their numbers BOX 2-2 for more information about interpreting pH values. of protons and electrons but differ in their atomic weights because of differing numbers of neutrons in the nucleus. The CASEPOINT© Jones & Bartlett Learning, LLC most common© Jones form of &oxygen, Bartlett for example, Learning, has eight LLC pro- 2-3NOT Margaret’s FOR blood SALE pH wasOR 7.28. DISTRIBUTION Is she suffering from acid tons and eightNOT neutrons FOR inSALE the nucleus, OR DISTRIBUTION giving the atom an osis or alkalosis? atomic weight of 16 atomic mass units (amu). But there are some isotopes of oxygen with only six or seven neutrons in the nucleus and others with 9 to 11 neutrons. The isotopes BUFFERS of oxygen thus range in atomic weight from 14 to 19 amu. © Jones &In Bartletta healthy Learning,person, body LLCfluids are delicately balanced© JonesSome & Bartlett isotopes are Learning, stable and maintain LLC constant charac- NOT FORwithin SALE narrow OR limitsDISTRIBUTION of acidity and alkalinity. This balancedNOT teristics. FOR SALE Others fallOR apart DISTRIBUTION and radiate (give off) subatomic chemical state is maintained in large part by buffers. particles and/or electromagnetic (energy) waves called Chemical buffers form a system that prevents sharp changes gamma rays. (Other types of electromagnetic waves are

© Jones visual& Bartlett light, ultraviolet Learning, light, LLC and x-rays.) Isotopes that fall© Jonesbonds &with Bartlett a variety Learning, of different LLC elements and can even NOT FORapart SALE easily OR are saidDISTRIBUTION to be radioactive. Radioactive elements,NOT covalently FOR SALE bond toOR other DISTRIBUTION carbon atoms to form long chains, also called radioisotopes, may occur naturally, as is the case most organic compounds consist of large, complex mole- with isotopes of the very heavy elements radium and ura- cules. The starch found in potatoes, the fat and protein in nium. Others may be produced artificially by placing the tissues, hormones, and many drugs are examples of organic atoms of lighter, nonradioactive elements in accelerators compounds. These large molecules are often formed from that smash their nuclei ©together. Jones & Bartlett Learning, LLCsimpler molecules called building© Jones blocks &, Bartlettor monomers Learning, LLC The radiation givenNOT off by FOR some radioisotopesSALE OR isDISTRIBUTION used in (mono- means “one”), which NOTbond togetherFOR SALE in long ORchains. DISTRIBUTION the treatment of cancer because it can penetrate and destroy The main types of organic compounds are carbohy- tumor cells. A growing tumor contains immature, dividing drates, lipids, and proteins. All of these organic compounds cancer cells, which are more sensitive to the effects of radia- contain carbon, hydrogen, and oxygen as their main ingre- tion than are mature body cells. The greater sensitivity of these dients. Carbohydrates, lipids, and proteins (in addition to younger© Jonescells allows & Bartlettradiation therapy Learning, to selectively LLC destroy minerals, vitamins,© Jones and & water) Bartlett must Learning,be taken in LLCas part them NOTwith minimal FOR damageSALE toOR normal DISTRIBUTION tissues. Modern radia- of a normalNOT diet. TheseFOR nutrientsSALE ORare discussedDISTRIBUTION further in tion instruments produce tremendous amounts of energy (in Chapters 17 and 18. the multimillion electron-volt range) that can destroy deep- seated cancers without causing serious skin reactions. In addition to its therapeutic values, radiation is exten- CARBOHYDRATES © Jones &sively Bartlett used in Learning,diagnosis. Radioactive LLC elements that can be© JonesThe building & Bartlett blocks ofLearning, carbohydrates LLC (kar-bo-HI-drates) are simple sugars, or monosaccharides (mon-o-SAK-ah-rides) NOT FORadministered SALE OR and DISTRIBUTION then detected internally to identify abnorNOT- FOR SALE OR DISTRIBUTION malities are called tracers. Radioactive iodine, for instance, (FIG. 2-8). (The word root sacchar/o means “sugar.”) Glucose can diagnose problems of the thyroid gland (see BOX 2-3). (GLU-kose), a simple sugar that circulates in the blood as a When using radiation in diagnosis or therapy, health- cellular nutrient, is an example of a monosaccharide. Two care personnel must follow strict precautions to protect simple sugars may be linked together to form a disaccha ride (see FIG. 2-8B), as represented by sucrose, or table sugar. themselves and the patient,© Jones because & Bartlettthe rays can Learning, destroy LLC © Jones & Bartlett Learning, LLC healthy as well as diseased tissues. More complex carbohydrates, or polysaccharides, consist of NOT FOR SALE OR DISTRIBUTIONmany simple sugars linked togetherNOT (FORsee FIG. SALE 2-8C). (The OR pre DISTRIBUTION- CHECKPOINT fixdi - means “two,” and poly- means “many.”) Examples of polysaccharides are starch, which is manufactured in plant 2-12 What word is used to describe isotopes that give off cells, and glycogen (GLI-ko-jen), a storage form of glucose radiation? found in liver cells and skeletal muscle cells. Carbohydrates © Jones & Bartlett Learning, LLC in the form© of Jones sugars and& Bartlett starches areLearning, important LLCdietary NOT FOR SALE OR DISTRIBUTION sources of energy.NOT FOR SALE OR DISTRIBUTION Organic Compounds The complex molecules that characterize living things are CASEPOINT called organic compounds. All of these are built on the 2-4 What type of carbohydrate was administered to Margaret element carbon. Because carbon atoms can form covalent in the case study? © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION HOT TOPICS BOX 2-3 Radioactive Tracers: Medicine Goes Nuclear

Like radiography, computed© Jones tomography & Bartlett (CT), and Learning, magnetic LLCto radiation in NMI is usually considerably© Jones lower& Bartlett than with Learning, LLC resonance imaging, nuclearNOT medicine FOR SALE imaging OR (NMI) DISTRIBUTION offers a x-ray or CT scan. NOT FOR SALE OR DISTRIBUTION noninvasive way to look inside the body. An excellent diagnos- Three NMI techniques are positron emission tomography tic tool, NMI not only shows structural details but also provides (PET), bone scanning, and the myocardial perfusion imag- information about body function. NMI can help diagnose can- ing (MPI) stress test. PET is often used to evaluate brain activity cer, stroke, and heart disease earlier than can techniques that by measuring the brain’s use of radioactive glucose. PET scans provide© Jones only structural & Bartlett information. Learning, LLC can reveal brain© Jones tumors because& Bartlett tumor Learning,cells are often moreLLC NOTNMI FORuses radiotracersSALE OR, radioactiveDISTRIBUTION substances that metabolicallyNOT active FOR than areSALE normal OR cells DISTRIBUTION and thus absorb specific organs absorb. For example, radioactive iodine is more radiotracer. Bone scanning detects radiation from a used to image the thyroid gland, which absorbs more iodine radiotracer absorbed by bone tissue with an abnormally high than does any other organ. After a patient ingests, inhales, metabolic rate, such as a bone tumor. The MPI test is used or is injected with a radiotracer, a device called a gamma to diagnose heart disease. A nuclear medicine technologist camera detects the radiotracer in the organ under study injects the patient with a radionuclide (e.g., thallium, techne- © Jones & Bartlettand produces Learning, a picture, which LLC is used in making a diagnosis.© Jonestium), and& Bartlett a gamma camera Learning, images the LLC heart during exercise NOT FOR SALERadiotracers OR areDISTRIBUTION broken down and eliminated through urineNOT and FOR later SALE rest. When OR compared, DISTRIBUTION the two sets of images help or feces, so they leave the body quickly. A patient’s exposure evaluate blood flow to the working, or “stressed,” heart.

OH HO © JonesOH & Bartlett Learning, LLC © Jones & BartlettO Learning, LLC NOT FOR SALE OR DISTRIBUTION NOTO FOR SALE OR DISTRIBUTION OH CH2 O O C A Monosaccharide O O

Sucrose (table sugar) O

HOCH2 HOCH2 © Jones & BartlettO Learning, LLCO © Jones & BartlettGlucose Learning, molecules LLC O NOT FOR SALEOH OR DISTRIBUTIONHO NOT FOR SALE OR DISTRIBUTION O HO O CH2OH O O OH OH C O O Glucose +F© Jonesructose & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE ORO DISTRIBUTION B Disaccharide C Polysaccharide

FIGURE 2-8 Examples of carbohydrates. KEY POINT A monosaccharide (A) is a simple sugar. A disaccharide (B) consists of two simple sugars linked together, whereas a polysaccharide (C) consists of many simple sugars linked together in chains. ZOOMING IN What are the© building Jones blocks & (monomers)Bartlett ofLearning, disaccharides LLCand polysaccharides? © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION LIPIDS the body’s structural materials, found in muscle, bone, and connective tissue. They also make up the pigments that give Lipids are a class of organic compounds that are not soluble hair, eyes, and skin their colors. It is proteins that make in water (hydrophobic). They are mainly found in the body each individual physically distinct from others. Proteins © Jones &as fat.Bartlett Simple fatsLearning, are made fromLLC a substance called glycerol© Jones & Bartlett Learning, LLC also serve functional roles. For instance, some act as trans- (GLIS-er-ol), commonly known as glycerin, in combination NOT FOR SALE OR DISTRIBUTION NOTporters, FOR SALEmoving ORsubstances DISTRIBUTION across cell membranes. Other with three fatty acids (FIG. 2-9). One fatty acid is attached to proteins, known as enzymes, promote metabolic reactions. each of the three carbon atoms in glycerol, so simple fats are Enzymes are discussed further shortly. described as triglycerides (tri-GLIS-er-ides) (the prefix tri- Proteins are composed of monomers called amino (ah- means “three”). Fats insulate the body and protect internal ME-no) acids (FIG. 2-10). Although only about 20 different organs. In addition, fats are the main form in which energy © Jones & Bartlett Learning, LLCamino acids exist in the body, ©a vastJones number & ofBartlett proteins Learning,can LLC is stored, and most cells use fatty acids for energy. NOT FOR SALE OR DISTRIBUTIONbe made by linking them togetherNOT in differentFOR SALE combinations. OR DISTRIBUTION Two other types of lipids are important in the body. Each amino acid contains an acid group (COOH) and Phospholipids (fos-fo-LIP-ids) are complex lipids contain- an amino group (NH ), the part of the molecule that has ing the element phosphorus. Among other functions, phos- 2 the nitrogen. These groups are attached to either side of a pholipids make up a major part of the membrane around carbon atom linked to a hydrogen atom. The remainder of living cells. Steroids are lipids that contain rings of carbon © Jones & Bartlett Learning, LLC the molecule,© symbolizedJones & by Bartlett R in FIGURE Learning, 2-10A, is different LLC in atoms. The most important sterol is cholesterol (ko-LES-ter-ol), each amino acid, ranging from a single hydrogen atom to a anotherNOT component FOR SALE of cellular OR DISTRIBUTIONmembranes (see FIG. 2-9B). NOT FOR SALE OR DISTRIBUTION complex chain or ring of carbon and other elements. These Cholesterol is also used to make steroid hormones, includ- variations in the R region of the molecule account for the ing cortisol, testosterone, and estrogen. differences in the amino acids. In forming proteins, the acid group of one amino acid © Jones &PROTEINS Bartlett Learning, LLC © Jonescovalently & Bartlett bonds with Learning, the amino LLCgroup of another amino NOT FORAll SALE proteins OR (PRO-tenes) DISTRIBUTION contain, in addition to carbon,NOT acid FOR (see SALE FIG. 2-10B) OR. This DISTRIBUTION bond is called a peptide bond. Many hydrogen, and oxygen, the element nitrogen (NI-tro-jen). amino acids linked together in this way form a protein, They may also contain sulfur or phosphorus. Proteins are which is essentially a long chain of amino acids. (Shorter

© Jones & Bartlett Learning,Glycerol LLC © Jonesin body & structure. Bartlett Collagen, Learning, for instance, LLC provides structure NOT FOR SALE ORH DISTRIBUTIONH H NOTto FOR bones SALE and cartilage. OR DISTRIBUTION Other proteins, known as globular proteins, consist of helices (or other simple shapes) folded H C H C HHC back on themselves into complex three-dimensional structures (see FIG. 2-10D, right side). Myoglobin, for example, is a O O O globular protein similar to hemoglobin that stores oxygen © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC O O O in muscle cells. Other globular proteins include hormones, NOT FOR SALE OR DISTRIBUTIONantibodies needed for immunity,NOT and FOR enzymes. SALE The ORoverall DISTRIBUTION C C C three-dimensional shape of a protein is important to its H CH H CH H CH function, as can be seen in the activity of enzymes. C HH C HH C HH Enzymes Enzymes (EN-zimes) are proteins that par- © JonesH CH & BartlettH CH Learning,H CHLLC ticipate in the© hundreds Jones of& chemicalBartlett reactions Learning, that take LLC place within cells. They act as catalysts (KAT-ah-lists), substances NOTH FORCH SALEH CHOR DISTRIBUTIONH CH NOT FOR SALE OR DISTRIBUTION that increase the speed of chemical reactions to a rate suf- CH H CH H CH ficient to sustain life. By controlling the activity of enzymes, the body controls which chemical reactions occur under H CH H CH H CH which circumstances. Because each enzyme works only on © Jones & BartlettH CHLearning,H LLCCH H CH © Jonesa specific & Bartlett substance, Learning, orsubstrate , and LLC does only one specific chemical job, many different enzymes are needed. Like all C HH H CH H CH NOT FOR SALE OR DISTRIBUTION NOTcatalysts, FOR SALE enzymes OR take DISTRIBUTION part in reactions only temporarily; H H CH H CH they are not used up or changed by the reaction. Therefore, H CH H CH they are needed in small amounts. Many of the vitamins and minerals required in the diet are parts of enzymes. H C H H CH © Jones & Bartlett Learning, LLCAn enzyme’s shape is important© Jones in its &action. Bartlett Just as Learning, the LLC H H shape of a key must fit that of its lock, an enzyme’s shape must NOT FOR SALE OR DISTRIBUTIONmatch the shape of the substrateNOT it FORacts on. SALE This so-called OR DISTRIBUTION Fatty Acids “lock-and-key” mechanism is illustrated in FIGURE 2-11. A Triglyceride (a simple fat) Because the hydrogen bonds that hold proteins in their shapes are weak, they are easily broken. Harsh conditions, such as extremes of temperature or pH, can alter the shape © Jones & Bartlett Learning, LLC of any protein,© Jones such as an& enzyme,Bartlett and Learning, destroy its ability LLC to CH3 H NOT FOR SALE OR DISTRIBUTION function. TheNOT alteration FOR ofSALE a protein’s OR shapeDISTRIBUTION so that it can no longer function is termed denaturation. Such an event is H C CH2 CH2 CH2 CCH3 always harmful to the cells. H3C CH3 You can usually recognize the names of enzymes because, with few exceptions, they end with the suffix ase- . H C © Jones & Bartlett3 Learning, LLC © JonesExamples & Bartlett are lipase, Learning,protease, and LLCoxidase. The first part of NOT FOR SALE OR DISTRIBUTION NOTthe FOR name SALE usually ORrefers DISTRIBUTION to the substance acted on or the type of reaction in which the enzyme is involved. HO NUCLEOTIDES B Cholesterol (a steroid) One additional class of organic compounds is composed of © Jones & Bartlett Learning, LLCbuilding blocks called nucleotides© Jones (NU-kle-o-tides) & Bartlett (FIG. 2-12) Learning,. LLC FIGURE 2-9 Lipids. A. A NOTtriglyceride, FOR a simple SALE fat, contains OR DISTRIBUTION A nucleotide contains: NOT FOR SALE OR DISTRIBUTION glycerol combined with three fatty acids. B. Cholesterol is a type of

steroid, a lipid that contains rings of carbon atoms. ZOOMING IN ■ A nitrogenous (nitrogen-containing) subunit called a How many carbon atoms are in glycerol? base (not to be confused with an alkali).

■ A sugar, usually a sugar called ribose or a related sugar chains© ofJones amino &acids Bartlett are sometimes Learning, called LLCpolypeptides.) called deoxyribose.© Jones & Bartlett Learning, LLC The linearNOT chain FOR of SALEamino acids OR can DISTRIBUTION fold into specific shapes NOT FOR SALE OR DISTRIBUTION ■ A phosphate group, which contains phosphorus. There because of hydrogen bonding between nonadjacent amino may be more than one phosphate group in the nucleotide. acids. The most common of these simple shapes is a helix (spiral) (FIG. 2-10C). The final, functional form of a protein depends on further interactions between these simple shapes Concept Mastery Alert © Jones &(see Bartlett FIG. 2-10D) Learning,. Some proteins LLC consist of multiple protein© JonesOut of & the Bartlett four types Learning, of organic compounds, LLC nucleotides NOT FORchains, SALE each OR folded DISTRIBUTION into a helix, coiled together into ropeNOT- FORand carbohydrates SALE OR contain DISTRIBUTION sugar, but proteins and lipids like structures (see FIG. 2-10D, left side). These proteins are do not. known as fibrous proteins, and they play important roles

R H R O H H HOHOAnabolism H O ©N JonesC C& Bartlett Learning,N C C LLC © JonesN C & CBartlettN C Learning,C+ LLCH O Catabolism 2 H NOT FOR SALEOH HOOR DISTRIBUTIONH NOTH FOR SALE OR DISTRIBUTIONOH H R H R Amino acid 1 Amino acid 2 A dipeptide B

Helix Fibrous protein Globular protein © Jones & Bartlett Learning, LLC (collagen) (myoglobin)© Jones & Bartlett Learning, LLC NOT FOR SALE ORCD DISTRIBUTION NOT FOR SALE OR DISTRIBUTION FIGURE 2-10 Proteins. A. Amino acids are the building blocks of proteins. Each amino acid contains an amino group and an acid group attached to a carbon atom. The remainder of the molecule (shown by R) can vary in 20 different ways.B. The acid group of one amino acid can react with the amino group of another forming a peptide bond. Further additions of amino acids result in formation of a polypeptide chain. C. Chemical attractions between nonadjacent amino acids form simple shapes, such as a helix. D. Fibrous proteins consist of multiple © Jones &protein Bartlett helices coiledLearning, together. GlobularLLC proteins consist of helices ©(or Jonesother simple & shapes)Bartlett folded Learning, back on themselves LLC into complex three- NOT FORdimensional SALE OR structures. DISTRIBUTION The characteristic shape of each protein is criticalNOT to FOR its function. SALE ZOOMING OR DISTRIBUTION IN Which part of an amino acid contains nitrogen?

S1 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION FIGURE 2-11 Diagram of enzyme action. KEY POINT An enzyme joins with substrate 1 (S1)

and substrate 2 (S2) and speeds up the chemical reaction in which the two substrates bond. Once a new product is formed from the substrates, the enzyme is released unchanged. ZOOMING IN How does the shape of the enzyme before the reaction compare with its shape after the reaction? © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

© Jones & Bartlett Learning, LLC © Jones & BartlettHigh-energy Learning, bonds LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Nitrogenous Phosphate Adenine Phosphate Phosphate Phosphate base

FIGURE 2-12 Nucleotides. A. A nucleotide consists of a nitrogenous base, a sugar, and one or more phosphate groups. B. ATP has high-energy bonds between the phosphates. When these bonds are broken, energy is released. © JonesZOOMING & Bartlett IN What does Learning, the prefix tri LLC- in adenosine triphosphate mean?© Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION The nucleic acids deoxyribonucleic acid (DNA) and vibrations of a single molecule to locomotion in an entire ribonucleic acid (RNA), involved in the transmission of organism. There are also less obvious forms of kinetic genetic traits and their expression in the cell, are com- energy. One is radiant energy, which consists of waves © Jones &posed Bartlett of nucleotides. Learning, These LLC are discussed in further detail© Jonestraveling & Bartlett through Learning, space. Sunlight, LLC heat, sound, and x-rays in Chapter 3. Adenosine triphosphate (ah-DEN-o-sene are examples. Another type of kinetic energy is electric NOT FORtri-FOS-fate) SALE OR ( ATP)DISTRIBUTION, the cell’s high-energy compound, isNOT FORenergy SALE, which OR reflects DISTRIBUTION the movement of electrons, as in also a nucleotide. The energy in ATP is stored in special electric currents passing through wires or along neurons. bonds between the nucleotide’s three phosphates (see ■ Potential energy is stored energy that can be used to FIG. 2-12B). produce activity. An example is gravitational energy, © Jones & Bartlett Learning, LLCthe energy of position in ©a gravitational Jones & field.Bartlett A skier Learning, at LLC NOT FOR SALE OR DISTRIBUTIONthe top of a hill, for instance,NOT possesses FOR SALEpotential OR energy DISTRIBUTION Metabolism that can be used to power downhill movement. Another All the life-sustaining chemical reactions that occur within example of potential energy is chemical energy, which the body systems together make up metabolism (meh- is stored in covalent bonds. As noted, glucose and ATP TAB-o-lizm). Metabolism can be divided into two types of contain chemical energy in the bonds that hold the activities:© Jones & Bartlett Learning, LLC atoms together.© Jones & Bartlett Learning, LLC Energy can be converted from one form to another ■ InNOT catabolism FOR SALE(kah-TAB-o-lizm), OR DISTRIBUTION complex substances NOT FOR SALE OR DISTRIBUTION (FIG. 2-14). For example, plants convert radiant energy from are broken down into simpler components (FIG. 2-13). the sun into chemical energy within a fructose (fruit sugar) For instance, proteins are broken down into amino molecule using an anabolic reaction. Body cells use a cata- acids. Further catabolic reactions involving these sim- bolic reaction to convert the chemical energy of the sugar ple substances provide energy to fuel cell processes in molecule into the chemical energy of ATP. Breaking the © Jones & Bartlettthe form Learning,of ATP. Chapter LLC 18 discusses these reactions© Jones & Bartlett Learning, LLC high-energy bonds in ATP can produce kinetic energy in the NOT FOR SALEin greater OR detail. DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

■ In anabolism (ah-NAB-o-lizm), simple substances are used to manufacture materials needed for growth, func- POPCORN tion, and tissue repair. Anabolism consists of building (synthesis), reactions, such as constructing proteins from amino acids. ©These Jones synthesis & Bartlett reactions Learning,are fueled LLC © Jones & Bartlett Learning, LLC by ATP. NOT FOR SALE OR DISTRIBUTION Catabolism NOTAnabolism FOR SALE OR DISTRIBUTION

ENERGY POP CORN Every body cell needs energy, and multiple body systems are involved© Jones in its & generation. Bartlett MuchLearning, of physiology LLC involves © Jones & Bartlett Learning, LLC tracingNOT matter FOR and SALEenergy through OR DISTRIBUTION various bodily processes, FIGURE 2-13NOT Metabolism. FOR SALE KEY POINTOR DISTRIBUTION Metabolism includes so it is helpful to understand its basic forms. two types of reactions. In catabolism, substances are broken down into their building blocks. In anabolism, simple components are built ■ Kinetic energy is the energy of movement. All matter that into more complex substances. We use the breakdown and building is in motion possesses kinetic energy, ranging from the of a simple word here as an example of these reactions. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

+ CO2 + H2O C6H12O6 + O2 CO2 + H2O + ATP © CarbonJonesWater & Bartlett Learning,Fructose LLC © Jones & Bartlett Learning, LLC NOTdioxide FOR SALEAnabolic OR DISTRIBUTIONCatabolic NOT FOR SALE OR DISTRIBUTION reaction reaction (apple tree) (body cells)

Chemical energy Chemical energy Kinetic energy Radiant energy (bonds) (bonds) (movement) © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC FIGURENOT 2-14 FOR Energy SALE and chemical OR DISTRIBUTION reactions. KEY POINT Chemical reactions areNOT one wayFOR to convert SALE energy OR from DISTRIBUTION one form to another because chemical bonds are a source of potential energy. ZOOMING IN Which chemicals combine to form glucose?

form of body movements. All energy conversions liberate 2-15 What is an enzyme? © Jones &heat, Bartlett which increases Learning, body LLC temperature. Chapter 18 dis©- Jones 2-16 & WhatBartlett is in a nucleotide,Learning, and whatLLC compounds are made NOT FORcusses SALE ATP OR generation DISTRIBUTION in greater detail. NOT FOR SALEof nucleotides? OR DISTRIBUTION 2-17 What are the two main types of metabolic reactions, CHECKPOINTS and what happens during each? 2-13 What element is the basis of organic chemistry? 2-18 Use two terms to describe the energy contained 2-14 What are the three main categories of organic in ATP. compounds? © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

“Good morning, Mrs. Ringland. How are you feeling I’ll check with your doctor first,” replied Angela. “But today?” asked Angela. when you do return home, you will need to make sure © Jones & Bartlett“Much Learning, better, thank LLCyou,” replied Margaret. “I’m so © Jonesthat you & drinkBartlett plenty Learning, of fluids.” LLC NOT FOR SALEgrateful OR that DISTRIBUTION my niece found me when she did.” NOT FORIt was SALE the end OR of anotherDISTRIBUTION long shift, and Angela “I’m glad too,” said Angela. “With the heat wave was at her locker, changing into a pair of shorts and we’re having, dehydration can become a serious a T-shirt. As she closed her locker, she thought of problem. Older adults are particularly at risk of dehy- Margaret once again. It always amazed her that chem- dration because with age, there is usually a decrease istry could have such a huge impact on the body as a © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC in muscle tissue, which contains a lot of water, and a whole. She grabbed her water bottle, took a long drink, relative increase in bodyNOT fat, FOR which SALE does not. OR So DISTRIBUTION older and headed out into the scorchingNOT heat.FOR SALE OR DISTRIBUTION adults don’t have as much water reserve as do younger In this case, we see that health professionals adults. But,” Angela continued as she flipped through require a background in chemistry to understand Margaret’s chart, “it looks like you’re well on your way how the body works—when healthy and when not. to© a fullJones recovery. & Bartlett Your electrolytes Learning, are back LLC in balance. As you learn© moreJones about & theBartlett human Learning, body, consider LLC YourNOT blood FOR pressure SALE is back OR to DISTRIBUTION normal, and your heart referring backNOT to thisFOR chapter SALE when OR necessary. DISTRIBUTION For rate is good too. Your increased urine output tells me more information about the elements that make that your other organs are recovering as well.” up every single substance within the body, see “Does that mean I can go home soon?” asked Appendix 1: Periodic Table of the Elements at the Margaret. back of this book. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC OVERVIEW NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION A detailed chapter outline with space for note-taking is on the online site. The figure below illustrates the main topics covered in this chapter.

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ElementsNOT FOR SALEChemical OR DISTRIBUTIONMixtures Acids, bases, IsotopesNOT FOR SALEOrganic OR DISTRIBUTIONMetabolism bonds salts compounds

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALEAtoms OR DISTRIBUTIONTypes Solvents NOT FOR RadioactivitySALE OR DISTRIBUTIONTypes Energy Protons Solution Water Catabolism Kinetic Neutrons Suspension Anabolism Potential Electrons Colloid Energy levels © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION pH Buffers Types Chemical equations

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOTIonic FOR SALECovalent OR DISTRIBUTIONCarbohydrates Lipids NOTProteins FOR SALENucleotides OR DISTRIBUTION Electrolytes Polar Monosaccharides Tr iglycerides Amino acids DNA Nonpolar Disaccharides Steroids Enzymes RNA Polysaccharides ATP © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FORKEY SALE TERMS OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION The terms listed below are emphasized in this chapter. Knowing them will help you organize and prioritize your learning. These and other boldface terms are defined in the Glossary with phonetic pronunciations.

acid catalyst glycogen protein amino acid © Jonescation & Bartlett Learning,ion LLC ©proton Jones & Bartlett Learning, LLC anabolism NOT FORchemistry SALE OR DISTRIBUTIONisotope NOTradioactive FOR SALE OR DISTRIBUTION anion colloid kinetic energy salt aqueous compound lipid solute atom denaturation metabolism solution ATP electrolyte molecule solvent base © Jones & Bartlett electronLearning, LLC nucleotide © Jones & Bartlettsteroid Learning, LLC bufferNOT FOR SALE ORelement DISTRIBUTION neutron NOT FOR SALEsubstrate OR DISTRIBUTION carbohydrate enzyme pH scale suspension catabolism glucose potential energy

© Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. Chapter 2 ■ Chemistry, Matter, and Life 37 © Jones & Bartlett Learning, LLC © Jones WORD& Bartlett ANATOMY Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Medical terms are built from standardized word parts (prefixes, roots, and suffixes). Learning the meanings of these parts 2 can help you remember words and interpret unfamiliar terms.

WORD PART MEANING© Jones & BartlettEXAMPLE Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION CHEMICAL BONDS co- together Covalent bonds form when atoms share electrons. MIXTURES aqu/e water In an aqueous solution, water is the solvent. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC heter/o- different Heterogeneous solutions are different (not uniform) throughout. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION hom/o- same Homogeneous mixtures are the same throughout. hydr/o- water Dehydration is a deficiency of water. -phil to like Hydrophilic substances “like” water—they mix with or dissolve in it. phob/o fear Hydrophobic substances “fear” water—they repel and do not dissolve in it. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ORGANIC COMPOUNDS NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION -ase suffix used in naming A lipase is an enzyme that acts on lipids. enzymes de- remove Denaturation of a protein removes its ability to function (changes its nature). di- twice, double A disaccharide consists of two simple sugars. glyc/o- sugar,© glucose,Jones sweet & BartlettGlycogen Learning, is a storage LLC form of glucose. It breaks down© to Jonesrelease glucose. & Bartlett Learning, LLC mon/o- one NOT FOR SALE InOR a monosaccharide DISTRIBUTION, “mono-” refers to one. NOT FOR SALE OR DISTRIBUTION poly- many A polysaccharide consists of many simple sugars. sacchar/o- sugar A monosaccharide consists of one simple sugar. tri- three Triglycerides have one fatty acid attached to each of three carbon atoms. METABOLISM© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ana-NOT FOR SALEupward, again,OR DISTRIBUTIONback Anabolism is the building up of simpleNOT substances FOR SALE into more OR complex DISTRIBUTION substances. cata- down Catabolism is the breakdown of complex substances into simpler ones. kine, kinet/o movement Kinetic energy is the energy of movement.

Fill in the Blanks © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC 1. The subunits of elements are . 4. Blood has a pH of 7.35 to 7.45. Gastric juice has a pH NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 2. The atomic number is the number of in an of about 2.0. The more alkaline fluid is . atom’s nucleus. 5. Proteins that catalyze metabolic reactions are called 3. A mixture of solute dissolved in a solvent is called . a(n) . © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC MatchingNOT Match FOR eachSALE numbered OR DISTRIBUTION item with the most closely related letteredNOT item. FOR SALE OR DISTRIBUTION 6. A simple carbohydrate such as glucose a. polysaccharide 7. A complex carbohydrate such as glycogen b. phospholipid 8. An important component of cell membranes c. nucleotide © Jones & Bartlett9. Examples Learning, include DNA, LLC RNA, and ATP © Jonesd. amino & Bartlettacid Learning, LLC NOT FOR SALE10. The OR basic DISTRIBUTION building block of protein NOTe. FOR monosaccharide SALE OR DISTRIBUTION

© Jones Multiple& Bartlett Choice Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 11. Which type of mixture is plasma with red blood 14. Which substance releases a hydrogen ion when cells “floating” in it? dissolved in water? a. compound a. acid b. suspension b. base c. colloid © Jones & Bartlett Learning, LLC c. salt © Jones & Bartlett Learning, LLC d. solution NOT FOR SALE OR DISTRIBUTION d. catalyst NOT FOR SALE OR DISTRIBUTION 12. What is the most abundant compound in the 15. Which element is found in all organic body? compounds? a. carbohydrate a. oxygen b. protein b. carbon © Jonesc. lipid & Bartlett Learning, LLC c. ©nitrogen Jones & Bartlett Learning, LLC NOTd. waterFOR SALE OR DISTRIBUTION d. NOTphosphorus FOR SALE OR DISTRIBUTION 13. Which compound releases ions when in solution? a. solvent b. electrolyte c. anion © Jones & Bartlettd. colloid Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION UNDERSTANDING CONCEPTS 16. Compare and contrast the following terms: 20. Compare and contrast carbohydrates, lipids, and a. proton, neutron, and electron proteins, and give examples of each. b. ionic bond and covalent bond 21. List the components of nucleotides, and give three c. anion and cation© Jones & Bartlett Learning, LLCexamples of nucleotides. © Jones & Bartlett Learning, LLC d. polar and nonpolar covalent bonds NOT FOR SALE OR DISTRIBUTION22. Define the term enzyme, NOTand discuss FOR the SALE relationship OR DISTRIBUTION e. acid and base between enzyme structure and enzyme function. 17. What are some of the properties of water that make it 23. What is the difference between catabolism and an ideal medium for living cells? anabolism? Give an example of each type of activity. 18. What is pH? Discuss the role of buffers in maintaining 24. Compare and contrast kinetic energy and potential a© steady Jones pH in& theBartlett body. Learning, LLC © Jones & Bartlett Learning, LLC energy, and give examples of each. 19. DescribeNOT FOR some SALEuses of radioactiveOR DISTRIBUTION isotopes in NOT FOR SALE OR DISTRIBUTION medicine.

CONCEPTUAL THINKING © Jones &25. Bartlett Explain the Learning, statement, “AllLLC compounds are © Jones29. Margaret & Bartlett was rehydrated Learning, with LLCan aqueous solution NOT FOR SALEcomposed OR ofDISTRIBUTION molecules, but not all molecules are NOT FORcontaining SALE 13.5 OR g/L DISTRIBUTION glucose and several salts, including compounds.” sodium chloride, potassium chloride, and sodium citrate. 26. Based on your understanding of strong acids a. Name the solution’s solute(s) and solvent(s). and bases, why does the body have to be kept at b. What is the meaning of the notation g/L? (Consult a close-to-neutral pH? the metric system chart in the Student Resources for Chapter 1, if needed.) 27. In the opening case© study, Jones Margaret’s & Bartlett blood testsLearning, LLC © Jones & Bartlett Learning, LLC c. Give the chemical formulas for sodium chloride showed that the percentage of red cells in her blood NOT FOR SALE OR DISTRIBUTIONand potassium chlorideNOT (consult FOR the SALEperiodic ORtable DISTRIBUTION was high. Explain how the high reading relates to of the elements in Appendix 1, if needed). Margaret’s condition. 30. Bacteria break down glucose (C H O ) into ethanol 28. Margaret was suffering from dehydration and 6 12 6 (C H OH) and carbon dioxide (CO ). hypernatremia. Use the glossary of word parts at the 2 5 2 a. Write a chemical equation to describe this chemical back© Jones of this book& Bartlett to define Learning, the word parts LLC in these © Jones & Bartlett Learning, LLC reaction. two terms. NOT FOR SALE OR DISTRIBUTION b. Is thisNOT chemical FOR reaction SALE anabolic OR DISTRIBUTION or catabolic?